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991.
Gandham Munikumari Ramaiah Konakanchi Venkata Bharat Nishtala Gondru Ramesh Laxma Reddy Kotha K. B. Chandrasekhar 《合成通讯》2019,49(1):146-158
Substituted heterocyclic (isatin) appended thiosemicarbazone ligands (L1–L3) are synthesized by condensation of substituted isatin molecule with N(4)-phenyl-3-thiosemicarbazide in good yields. The palladium(II) complexes are synthesized from ligands (L1–L3) and PdCl2, with a general formula [PdCl(X-C15H10N4OS)] where X?=?5-chloro (1), 5-bromo (2), and 5-nitro (3). Both analytical and spectroscopic methods have been used for the analysis and characterization of the synthesized compounds. The antimicrobial activity results observed that complexes, 1 and 2 have registered potent antibacterial activity against B. subtilis and K. pneumoniae and also complex 2 has shown good antifungal activity against the micro organisms. The antioxidant activity analysis revealed that the complex 3 showed significant activity with IC50 values 7.24?±?0.09?µM. Moreover, the in vitro antiproliferative activity results suggested that complex 3 exhibited high activity against HeLa cell line compared with the standard with the IC50 value 16.52?±?1.08?µM. The docking results correlate well. 相似文献
992.
Although the hard template method is often employed to prepare N-doped mesoporous carbon(N-MC), the removal of the silica template commonly involves theuse of highly toxic HF or repeated treatment with NaOH solution. Herein, we reported a polyvinylidene fluoride-assisted one-step method for synthesis of N-MC, namely the silica-free N-MC can be prepared via temperature-programmed thermal treatment of a slurry obtained by dispersing nano-silica into a solution containing sucrose, urea, oxalic acid, polyvinylidene fluoride and dimethylacetamide. The resulting N-MC, which owns 3.47%(mass fraction) nitrogen and a surface area of 929 m2/g, is a highly suitable support of Pd catalyst used in hydrodechlorination of 2,4-dichlorophenol, with its performance being much better than those of MC and activated carbon. The excellent catalytic hydrodechlorination activity of the Pd/N-MC catalyst can be attributed to its strong metal-support interaction, which results in a good Pd dispersion and high resistance to the growth of nanosized Pd under reaction conditions. 相似文献
993.
The kinetics and mechanism of processes of reduction of Pd(II) complexes with a number of inorganic (NH3 , Cl– , etc.) and organic (ethylenediamine, glycine, -alanine, etc.) ligands on a dropping-mercury electrode and a Pd electrode in solutions with various concentrations of ligands, hydrogen ions, and supporting electrolytes are reviewed. The nature of electrochemical and chemical steps of processes of reduction of various complexes of Pd(II) is discussed.Translated from Elektrokhimiya, Vol. 40, No. 12, 2004, pp. 1494–1502.Original Russian Text Copyright © 2004 by Kravtsov. 相似文献
994.
The deposition and ripening of Pd atoms on the MgO(1 0 0) surface are modeled using kinetic Monte Carlo simulations. The density of Pd islands is obtained by simulating the deposition of 0.1 ML in 3 min. Two sets of kinetic parameters are tested and compared with experiment over a 200-800 K temperature range. One model is based upon parameters obtained by fitting rate equations to experimental data and assuming the Pd monomer is the only diffusing species. The other is based upon transition rates obtained from density functional theory calculations which show that small Pd clusters are also mobile. In both models, oxygen vacancy defects on the MgO surface provide strong traps for Pd monomers and serve as nucleation sites for islands. Kinetic Monte Carlo simulations show that both models reproduce the experimentally observed island density versus temperature, despite large differences in the energetics and different diffusion mechanisms. The low temperature Pd island formation at defects is attributed to fast monomer diffusion to defects in the rate-equation-based model, whereas in the DFT-based model, small clusters form already on terraces and diffuse to defects. In the DFT-based model, the strong dimer and trimer binding energies at charged oxygen vacancy defects prevent island ripening below the experimentally observed onset temperature of 600 K. 相似文献
995.
基于微观IBM理论,提出转动诱导出玻色子量子相变的一种可能途径:一旦原子核在受到高能激发或作快速旋转时,假如外界提供的能量足以使玻色子完成拆对顺排,则核处于集体相与单粒子态的共存相,其特征是出现较密集的能谱;假如能量不足以完成拆对或顺排,可能发生两种情况之一,当核旋转达到某个临界转动频率ωc时,或者一个高角动量的玻色子脱离“集体”而“游离”出来,或者发生一个高角动量的玻色子转变为一个低角动量的玻色子,核仍旧处于集体相;均会伴随出现光辐射,产生基态带的一条能级——相变信号.正是这类玻色子相变导致了原子核的量子相变.本物理图像统一了玻色子拆对顺排相变和退耦释放光子相变的描述.以100Pd核的14+1,14+2和14+3态的产生机理为例,对模型作了仔细说明. 相似文献
996.
H. Shiroishi T. Oda H. Sakashita N. Fujima 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,43(1-3):129-132
We have studied the electronic structure of the carbon nanotubes which
include Fe atomic wire with using the density functional theory.
As the stable geometries, we obtained the straight and zigzag wires,
which have ferromagnetic and antiferromagnetic alignments, respectively.
The antiferromagnets consists of the two ferromagnetic dimers which
couple in antiparallel alignment.
We presents the band dispersions and the density of states for the
magnetic nanotubes.
The electronic structure at the Fermi level consists of the
Fe 3d and C 2pπ states, which shows a strong hybridization
between them. 相似文献
997.
用pH电位法测定40%(V/V)二(口恶)烷-水介质中(I=0.1,25±0.1℃)Pd(Ⅱ)A(bpy、trp~-)-ATP~(4-)体系形成三元混配合物Pd(bpy)(ATP)~(2-)和Pd(trp)(ATP)~3的稳定常数,其lgK_(Pd(A)(ATP)~(2-))~(Pd(A))值分别为5.16和4.11,Jlgk值为-0.02和-1.08,并与lgK_(Pd(phen)(ATP)~(2-))~(Pd(A))-作了比较,其稳定顺序为Pd(phen)(ATP)~(2-)〉Pd(bpy)(ATP)~2〉Pd(trp)(ATP)~(3-).这一变化规律可从配体间πA~πB的合作效应及配体A和ATP~4间芳环堆积作用获得满意解释. 相似文献
998.
INTRODUCTIONPalladiumcomplexesplayanimportantroleinmanycatalyticreactions,especial-lyincarbonylationofolefins.InordertostudytherelationshipbetweenthestructureandproPertyofpalladiumcomplexcatalyst,thetitlecomplexwassynthesizedanditsstructurewascharacterizedbyX-raydiffractionmethod.2EXPERmENT2.1SynthesisAmixtureofmorpholine(o-lmol)andCuCl(O.2mol)inmethanol(8OmL)wasrefluxedfor6h.AftercoolingthesolutionwasfilteredrePeat-edlyunti1theclearfiltratewasobtained.BrownCuCl.C'H,NOcrystalswer… 相似文献
999.
用元素分析、热脱附和H_2还原脱附等方法分析了Pd/γ-Al_2O_3、Pd/MgO、Pd/TiO_2溶剂化金属原子浸渍(SMAI)催化剂的表面组成和孔结构。结果表明Pd颗粒表面覆盖着一些有机碎片,这些碎片主要由C_1和少量C_2,C_3及C_3以上物种组成。SMAI催化剂的比表面积均高于相应纯载体的比表面积。而平均孔径均小于后者,CO_2甲烷化反应中,SMAI催化剂的活性均高于相应的普通浸渍法(CI)催化剂,而活化能却低于后者。在SMAI催化剂上CO_2甲烷化反应机理与Solymosi机理相同。 相似文献
1000.
溶胶-凝胶法制备钯催化剂的织构与性能 总被引:1,自引:0,他引:1
采用溶胶-凝胶法制备了Pd/Al2O3催化剂,用LLS(激光光散射)、XRD和BET等技术考察了溶液pH值对所成胶体粒子流体力学半径、相应催化剂产品孔径分布及热稳定性的影响.研究发现,由pH=4.1的胶体制备的催化剂具有良好的热稳定性和CO、C3H6的氧化活性.氧化镧添加剂可抑制Al2O3载体在高温下由γ相向α相的转化,同时也促进了催化剂上Pd粒子的生长. La2O3可提高新鲜Pd催化剂的氧化活性,但对老化后催化剂活性的提高无促进作用. 相似文献